1-First Step: Gather and Prepare Ingredients Begin by placing 1 tablespoon of unsalted butter in an 8-ounce microwave-safe mug. I always recommend using a shorter, wider mug for even cooking and to prevent any overflow, which keeps your microwave clean. Measure out the rest of your ingredients like 4 teaspoons of packed light brown sugar, 1 tablespoon of granulated sugar, ¼ teaspoon of vanilla extract, a pinch of salt, 1 egg yolk, 3 tablespoons of all-purpose flour, and 2 tablespoons of semisweet chocolate chips to have everything at hand.

2-Second Step: Melt the Butter Microwave the butter in the mug for about 30 seconds until it’s mostly melted. This step is crucial as it creates a smooth base for mixing; stir it gently to ensure it’s evenly distributed. If your microwave varies in power, keep an eye on it to avoid overheating, which could affect the final texture of your cookie in a mug.

3-Third Step: Mix the Sugars and Flavors Add the 4 teaspoons of packed light brown sugar, 1 tablespoon of granulated sugar, ¼ teaspoon of vanilla extract, and a pinch of salt to the melted butter in the mug. Stir everything together until it’s well combined; this builds the sweet foundation. For dietary adaptations, if you’re watching calories, you could use a sugar substitute here to keep it fitting your needs.

4-Fourth Step: Add the Egg Yolk and Flour Next, mix in the 1 egg yolk until the mixture is smooth and creamy; this helps bind the ingredients. Then, stir in the 3 tablespoons of all-purpose flour just until combined overmixing can make it tough, so go easy. If you’re making a gluten-free version, substitute with gluten-free flour here to maintain that perfect cookie in a mug consistency.

5-Fifth Step: Incorporate the Chocolate Chips Fold in most of the 2 tablespoons of semisweet chocolate chips, saving a few for the top. This adds those delightful chocolate bursts; for variations, you could mix in my classic chocolate chip cookies recipe ideas if you want to experiment. Spread the batter evenly in the mug for uniform cooking.

6-Final Step: Microwave and Cool Microwave on high for 45 seconds to 1 minute, watching closely until the dough puffs up and looks dry on top the total cook time is just 1 minute, so timing is key. Let it cool for a few minutes before digging in, as this makes it safer and improves the texture. With a preparation time of only 2 minutes, this cookie in a mug is ready fast, and one serving offers about 524 calories with 61g carbs, 7g protein, and 28g fat, making it a balanced treat.